bronander



March 13, 1945. w. B. BRONANDER COOLING FINS Filed NOV. 5, 1942 3Sheets-Sheet 1 m u I .0

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Filed No v. 5, 1942 3 Sheets-Sheet 2 INVENTOR. Wl'lfieim BBrmamZer Q WWW A TTORNEY W. B. BRONAN DER COOLING FINS March 13, 1945.

Filed um 5, 1942 3 Sheets-Sheet 3 I, v I

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INVENTOR.

Wilhelm 3.252'022m2der ATTOJ? y Patented Mar. 13, 1945 fifltlhliid coonWilhelm B. Bronander, hiontclair, N. .U. Application November 5, 19442,Serial No. 464,628

4 Claims sci. est-2st) This invention relates to cooling fins.

It is the usual practice to form cooling fins integral with the part tobe cooled or to braze or solder fins thereto. The casting of integralflns involves the use of expensive patterns and fins so cast are brittleand easily broken. Fur

thermore, the casting process limits materially the number of fins perunit of length since they must be spaced apart materially in order to becast. Brazing, welding or soldering fins to the part to be cooled isexpensive and time consuming and does not, as a rule, result in a rigidand emcient heat conducting joint.

It has been found that air cooling with cool ing fins is eifective onthe surface of the element to be cooled on the side nearest the airinlet or air impact, but that the remote surfaces are not effectivelycooled since the air is deflected outwardly by the surface first engagedor contacted. This is particularly true of engine cylinders, cylinderheads, and like parts.

At the present. time, under war conditions there is an ever increasingdemand for aircraft engines with higher compression, more power, andmore speed. With higher compression great heat is developed and greaterheat dissipating capacity must be provided. In aircraft engines,therefore, one of the big problems is the effective cooling oi theengine and the power of the engine is limited by the capacity of thecooling means to dissipate the heat. Deflectors carried by engine partshave been used to deflect the air to parts remote from the air inlet orinflow but such deflectors are spaced from the cooling fins and do notconfine the air to passages between the fins. The deflectors themselvesare more efiectively cooled than the engine.

comparatively thin fins of metal, such as aluminum, have been used tosome extent, but such fins, due to the ductility of the metal, areeasily bent or warped out of shape, thus impeding the passage of airtherebetween.

This invention has for one of its objects to provide a cooling finstructure that is simple and.

practical and can be economically manufactured and secured to the partto be cooled.

Another object oi the invention is to provide a simple and practicalconnection between the fin and cylinder or member to which the fin isapplied, so constructed that the fin will be firmly and rigidly anchoredand the connection will effectively conduct the heat.

Another object of the invention is to provide a a cooling fin and airdeflector so designed that the deflector will not only deflect the airand confine it to the passages between the fins but will serve toincrease the radiating and heat dissipating capacity 01 the fins.

Another object of the invention is to provide simple and practical meansfor maintaining cooling fins in proper spaced relation.

Another object of the invention is to provide simple and practical meansfor deflecting the cooling air as it passes around the element to becooled and between the fins so that the portion of the element or memberon which the fins are mounted, remote from the portion first engaged bythe air, will be efiectively cooled.

Further objects of the invention will appear from the followingspecification taken in connection with the drawings which form a part ofthis application, and in which Fig. l is a plan view of a member to becooled tially on line 5-5 of Fig. 1 and on an enlarged scale;

Fig. 6 is a sectional elevation on an enlarged scale taken substantiallyon line 6 -45 of Fig. 1; Fig. 7 is a vertical sectional elevation of acylinder and cylinder head having mounted thereon fins constructed inaccordance with the invention;

Fig. 8 is a vertical sectional elevation at right angles to Fig. 7 andtaken substantially on line 8-8 of Fig. 7, this view being broken away;

Fig. 9 is a view similar to Fig. 5 but illustrating a slightly modifiedform of fin structure; and

Fig. 10 is a view similar to Figs. 5 and 9 but illustrating anothermodification of the fin structure;

The invention briefly described comprises the combination of a member tobe cooled, such as a cylinder, cylinder head or like part, havinggrooves therein, and cooling fins secured in the grooves and includingor having means incorporated therein arranged to engage other fins andmaintain the fins in proper spaced relation. Defiecting means areprovided on the fins whereby the air is confined and directed to remotesurfaces of the part to be cooled and these means are preferablyintegral with the fins and thus increase the capacityfor heatdissipation.

In the structure illustrated this is accomplished by providing certainof the fins with means arranged to overlap certain other fins,.therebyconfining the space between certain portions of the fins and the wall onwhich the fins are mounted, thus providing a passageway for the airpassing between the fins and causing this'air to be deflected inwardlyagainst the portions of the wall remote from the portions initiallyengaged or impacted by the air. The fins are preferably secured in thegrooves by compressing material disposed therebetween, thereby forcingthe fins laterally into firmly anchored position against the walls ofthe grooves.

Further details of the invention will appear from the followingdescription. I

The fin and fin structure involving the invention may be mounted on anymember or element to be cooled such, for instance, as a cylinder wall,cylinder head, and so forth.

In the form of the invention illustrated particularly in Figs. 1 to 6inclusive, there is shown a member having a wall 20 provided with aplurality of grooves 2| which are usually disposed either in spiral formor in parallel relation.

In the form of the invention shownin Fig. 1, the'flns are formed of astrip of material which is bent or formed in any suitable manner, as byextrusion, into the shape shown in Fig. 4. In this figure the fincomprises walls 22 and 23 which are preferably substantially paralleland an intermediate connecting portion 24 which takes the form of aninverted V. The fln itself, including the two walls and connectingportion, is W shaped. It will be noted that the wall 22 is longer thanthe wall 23 for reasons hereinafter explained.

In Fig.1 the fin structure mounted in each peripheral or circumferentialgroove in the wall 20 comprises two semi-circular sections 30 and 3|.These sections are formed by bending the strips above described into asemi-circumference. These half sections are then placed in a groove andthe intermediate portion 24 between the fin walls 22 and 23 iscompressed as shown at the upper portion of Fig. 5. As this material 24is compressed it will be forced toward the bottom of the groove, therebyexerting a lateral pressure on the Walls 22 and 23 and forcing thesewalls into tight and firm gripping engagement with the walls of thegroove.

- For a portion of its length each fin section bent at right angles tothe remaining portion of the wall. These bends are made before the finsare secured in the grooves and do not interfere with the caulking ortamping of the portion 24 since the fins are successively caulked andthe flange of one fin overlaps the next fin. This bent portion forms aflange which overlaps the shorter wall 23 of the next adjacent doublewalled fin, after the fins have been secured in place, and engages, asshown at 32, the longer wall 22 of the next adjacent fin. The flangethus forms passage chambers 34 and 35 bounded by the fin walls and bythe outer wall of the member 20. As shown in Fig. 2, the cooling airenters at the top of the figure and passes around the wall, beingdeflected .by the flanges '36 so that the cooling air will engage theportions of the wall 2!] remote from the portion engaged by the enteringair.

The cooling air leaves the fins and flanges 36 at the points X and Yshown in Fig. l.

The flanges, in addition to deflecting the air.

act as heat radiating or dissipating surfaces, thus materiallyincreasing the radiating capacity of the engine fins. p In order tomaintain the fin walls in proper spaced relation and preferably inparallel relation to each other so that the passage of air therebetweenwill not be impeded, the walls are provided with indented or offsetportions 40 which are preferably staggered, as shown in Fig. 3. Theseoffset portions engage the next adjacent walls, as shown in Fig. 6, andsince they extend inwardly from the outer edges of the fins a relativelyshort distance, the passage of air between the fins is not impeded.

Fig. '7 illustrates an engine cylinder having a cylinder head 5| mountedand secured thereon as by the threaded connection 52. The cylinder headmay be formed of aluminum.

The cylinder wall ill is circumferentially grooved, as shown at 51, andfins are secured thereto in the manner hereinabove described andillustrated in Figs. 1 to 6 inclusive.

The cylinder head ii is provided with grooves and fin sectionsdimensioned to fit the grooves 55 are bent longitudinally to conform tothe contour of the grooves. then secured therein by compressing thematerial disposed between the fin walls in the manner above describedand have deflecting flanges 56 which are formed before the fins areanchored and extend over the outer ends of certain of the fin walls sothat these ends will overlap other walls'and contact still furtheradjacent walls, in the manner shown in Fig. 5. The fins 51 shown in Fig.7 which are disposed around the cylindrical portion of the head 5| arepreferably mounted in the manner shown in Fig. 1.

Fig. 9 illustrates a slightly modified form of 40 fin structure in-whichthe two walls 60 and 6| groove.

are formed of separate strips. One edge of each strip is bent back onitself, as shown at 62 and 63, and the portions 62 and 63 are disposedin abutting relation and folded edges of the fin walls Bil and Si arepositioned in the groove 64 formed in the wall 65 of the part to becooled. After the fins are thus positioned in the groove the materialformed by the parts 62 and 63 is compressed, thereby forcing thismaterial toward the bottom of the groove and forcing the walls 62 and 63laterally into tight gripping engagement with the walls of the groove64.

As in the form of the invention illustrated in Fig. 5, a portion of eachwall 60 is formed longer than or extends beyond the outer end of thewallfii. Before the fin walls have been anchored in the groove thisextending portion is bent laterally and the flange thus formed overlapsone fin wall and engages the next one.

In Fig. 10 a three piece construction is illustrated comprising fiatstrips or walls 10 and II and an intermediate folded portion 12positioned between the walls 10 and II. This intermediate portion 12 isdepressed to anchor the walls in the The flanges are formed in the samemanner as that above described.

The fins may be of any desired width and, as shown in Fig. '7, may betapered in width since the inner ends of the cylinders do not require asgreat an amount of radiation as the outer ends thereof.

Although certain specific embodiments of the invention have beenparticularly shown and described, it will be understood that theinvention is capable of modification and that changes in These fins arethe construction and in the arrangement of the various cooperating partsmay be made without departing from the spirit or scope of the vinvention, as expressed in the following claims.

What I claim is; Y

1. In combination, a member to be cooled having a plurality of groovestherein arranged side by side, a plurality of double walled fins securedin said grooves, the space between the portions of said double wallsdisposed in the grooves being filled inby material compressed to securethe fin walls in tight gripping engagement with the walls of the groove,one wall of certain fins being longer than the other wall and being bentlaterally to form a flange extending over the shorter wall of the fin onone side thereof disposed in the next adjacent groove, whereby each rialcompressed to secure the fin walls in tight gripping engagement with thewalls of the groove, one flnwallin each groove being longer than theother wall and being bent laterally to form a flange extending over theshorter wall of the fin on one side thereof disposed in the next 30flange adapted to extend over the shorter wall ,adjacent groove, wherebyeach unit can be anchored by compressing material between the wallswithout interference or the flange, said 'fiange engaging the outeredges of a plurality of posed between the inner edges of the walls andcompressed to force the fin walls into firm engagement with the walls ofthe groove, one fin wall of certain of the fin units being 'bentlaterally in a direction away from the other fin wall to form a flangeengaging the nearest fin wall of the next adjacent unit, whereby saidcompressible material between the walls of said unit can be engaged andcompressed, said flange engaging the outer edges of a plurality of finwalls confining the spaces therebetween.

4. In combination, a member to be cooled having substantially parallelgrooves therein, iln

units secured in said grooves, each unit comprising a pair of parallelwalls, and material: disposed between the inner edges of the walls andcompressed to force the fin walls into firm engagement with the walls ofthe groove, one fln wall being longer than the other well and being bentlaterally away from said wall to form a of the next unit,

wmHELM B. naommnm'

